I will eventually be running either 2 ps-2's or 2 x-box's, 4 LCD screens, and a dvd player. Not too mention subwoofer amp, component amp, H/U, and the various other things.

At what point should I place a second battery in my vehicle (possibly deep cycle marine battery?).

I realize that the battery is often not used when the car is running, but if/when the amplifier can't handle the load and things start to dim, wouldn't it be better for those items to place a load on a different battery than my main one? Not too mention if I happen to let someone watch a movie and I don't want the car running, I'd rather kill a second battery than need a jump start...

Also, everyone is throwing around "red top" and "yellow top". Are those specific brands? I don't mind buying batteries at sears, walmart, or wherever as long as they're decent, but are the yellow tops deep cycle and the red tops not?

Thanks for any information. One more question, when I install the second battery, it needs to be well ventilated... If I ran it in my trunk, would I need to somehow seal it from the rest of the car, but yet run vents to the outside?

Re: 2nd Battery question - Lots of load..

red top and yellow top are made by optima, if you are intersted in killing your second battery completely then you will need a yellow top.....a regualr battery can only be drained completely before it dies for good, optima yellows can be discharged many times...red tops are meant for starting batteries, now if you buy an optima you don't need vents, you can mount them anyway possible.....thats why they are perfect for in the car use. you will also definetly want a larger alternator......thats a lot of crap........upgade all your grounds under the hood to 00 or 0 wiring.....

Re: 2nd Battery question - Lots of load..

Sounds like a lot of stuff for a stratus. Can't say I'd recommend that especially for a novice. If the car isn't going to be running while all these devices are running I would put in a circuit breaker (along with the isolator) for the second battery. This way when the engine isn't running you can simply and positively disconnect your battery from the rest of the vehicles electrical system.